#include <stdio.h>

int main()
{
    long long y,t;
    
    scanf("%lld %lld",&y,&t);
    
    if(t==0){
        printf("NO\n");
        printf("YES");
            }
    if(t!=0){
        if(y>0&&y%2==0){
            printf("NO\n");
            printf("NO");
                       }
        else if(y>0&&y%2!=0){
            printf("NO\n");
            printf("YES");
                            }
        else if(y<0&&-y%2==0){
            printf("YES\n");
            printf("NO");
                            }
        else if(y<0&&-y%2!=0){
            printf("YES\n");
            printf("YES");
                             }
        else if(y==0){
            printf("NO\n");
            printf("NO");
                     }
            }
    return 0;
}